Scientists Discover 'RUST on MOON' Link It to Earth’s Atmospheric Oxygen

The Moon is showing signs of an unexpected transformation: it's developing rust. Scientists have detected hematite, a form of iron oxide, on the lunar surface, particularly near the poles. The discovery is puzzling because rusting normally requires oxygen and water, both of which are scarce on the Moon.

According to Nature, Ziliang Jin, a planetary scientist at Macau University of Science and Technology in China, said that the findings help in understanding Earth's deep link to the Moon. Ziliang and his colleagues reported their findings earlier this month in Geophysical Research Letters.

The team believes oxygen from Earth's atmosphere is transported to the Moon. Charged particles from the Sun reach both Earth and the Moon most of the time. However, for about five days each month, when Earth passes between the Sun and the Moon, most solar particles are blocked. During this period, the Moon is mainly exposed to particles originating from Earth's atmosphere, a phenomenon called “Earth wind.”

As explained by Sky At Night Magazine, Earth's magnetotail reduces solar wind exposure, allowing oxidation to occur during certain lunar phases.

The researchers tested this idea in the laboratory using an Earth wind simulation. Hydrogen and oxygen ions were accelerated to high energies and sent into single crystals of iron-rich minerals similar to those found on the Moon. Some of the crystals changed into hematite when hit with high-energy oxygen, while pelting hematite with hydrogen caused some of it to revert to iron.

“This is a great experiment,” says Shuai Li, a planetary scientist at the University of Hawaii at Manoa, who led the team that made the 2020 discovery.

In 2020, India’s Chandrayaan-1 mission had already spotted hematite near the Moon's poles. Understanding lunar rusting could impact future lunar missions, including equipment design and resource utilization.

“Our findings offer a practicable explanation for the formation and distribution of lunar hematite,” the researchers wrote in the study, titled 'Earth wind-driven formation of hematite on the lunar surface.'

“These findings provide valuable insights into the widespread distribution of lunar hematite and indicate a long-term material exchange between Earth and the Moon.”

The study concludes that Earth wind plays a key role in forming and distributing hematite, highlighting a long-term material exchange between Earth and the Moon.